Free Flight: Duration
FOR FOUR or five years now, I've been corresponding with Danish Wakefield flier Jorgen Korsgaard. (Actually, he lives just across the border in Germany.) Jorgen has also been known to dabble with towline gliders from time to time; his "Hot-Max" F1H design was named to the Top Ten list in the 1982 NFFS Symposium. He recently sent along plans for his AK-2 F1A model, designed for his teenage son Anders. At the Stonehenge Cup last Easter in England, Anders finished a credible 27th out of 48 flying the simple straight-tow model. But Jorgen can tell it better:
Free Flight: Duration
STAYING IN SIGHT: At my last contest, I launched into the same thermal with two other Wakefields. The other models had similar color schemes-red or orange D-box with white tissue covering the rest of the wing. My model had a solid black underside. The difference was amazing; in the bright sun, the other two models were hard to pick up overhead. The black, however, really popped out. I have been using black undersides on wings for several years now, and I'm convinced that it is the easiest to see when the model is overhead. In fact, I even started using black for the pylon and rudder so the model could be seen longer downwind.
Free Flight: Duration
ON MY LAST half-dozen Wakefield wings I have been using a composite D-box construction. Basically, this consists of a very stiff carbon-fiber spar, a D-box shell of either Kevlar or carbon, and precious little else. The trailing edge is a piece of .030 by 1/8 inch carbon. So the 1/16 thick balsa ribs end up with a glue joint that's only about 1/32 by 1/16. That's not much. To help hold the trailing edge on, I began using carbon fiber capstrips on the top and bottom of each rib, running from the spar back to the trailing edge. Typically, the cap was .003 inch thick carbon, stripped to 1/16 width.
Free Flight: Duration
COVERING CONFUSION: Back in the 1950s, it was simple. There were just two choices-Japanese tissue or silkspan. Sure, some folks used silk, but it really soaked up the dope. The color options for silkspan were limited to white, red, and yellow. So most of the time, I used tissue: light, lots of colors, and a nickel a sheet. Then along came the plastic wraps-literally. But after a few tries in the mid-1950s, I decided plastic wraps were better left for leftovers. Then the made-for-models plastic films were developed; too heavy. I did try some clear Micafilm a few years back. The weight wasn't bad, but it didn't give the wing the same stiffness that good old tissue-and-dope did.
Free Flight: Duration
IN THE AUGUST COLUMN, I mentioned one of the Ukrainian Wakefields had a near-miss with the ground when the flier stretched the delayed prop release (DPR) out a bit too long. (He maxed anyway.) I had thought that the flier was Eugeny Gorban, but after the August column was in production, Tucson F1B flier Vern Walters called with a correction. The flier was actually Yuri Blachevich, who ended up in seventh place. Vern should know-he and Sal Fruciano spent the week at the field with Yuri and the winner, Alexander Andriukov. Vern said that he watched Yuri launch; the delay was long, and the model stalled, nearly hit the ground, then zoomed up to max. Andriukov was also watching. He shortened the delay time slightly before launching and had no problems.
